This application relates to an air separation module having a manifold wherein the flow direction is selected to increase the efficiency of separation.
Air separation modules are known and typically include a plurality of canisters including fibers. The canisters extend from an inlet end that receives hot air, such as from a compressor in a gas turbine engine. Tube sheets are spaced from each other within the canisters. Hollow fibers are constructed to connect the tube sheets. The hollow fibers are constructed such that oxygen can permeate the fibers and move into the chamber surrounding the fibers. Nitrogen passes through the fiber to a downstream chamber. The hot air passes through the canisters, and the fibers serve to separate nitrogen and oxygen. Typically, oxygen moves outwardly into a surrounding jacket manifold, and passes to an oxygen outlet. The nitrogen flows downstream through the canisters and to an outlet manifold.
The nitrogen may be utilized as inert gas on an aircraft, such as to prevent explosion or flame in a fuel system or for use in a fire extinguishing system. The known canisters typically must be heated to provide efficient operation.
Particularly, under some conditions, the air may not be as hot as desired. As an example, in an aircraft that includes such a module, warm-up, cruise conditions, or descent flight phases may result in the temperature not being maintained sufficiently high to generate nitrogen efficiently.
In the prior art modules, the separated oxygen flow would typically leave the oxygen manifold at the inlet end of the module.